The Journey of Flight.pdf - Valkyrie Cadet

Chapter Chapter 15 15 - - Helicopters, Helicopters, STOLs, STOLs, VTOLs, VTOLs, and and UA UAVs UA Vs
thrust to the horizontal engines. The speed was around 400 mph.
The Harrier. The Harrier-or the AV-8A, as the Marines call it, has exceeded Mach 1 in a shallow
dive and has achieved very close to sonic speed in level flight. In a trade-off to achieve VTOL, the
Harrier sacrifices both top fighter performance and heavy-attack payload. Nevertheless, it is a warplane
that can fight when others cannot. You will recall that the Harrier was first used in combat by the
British during the Falkland Island crisis in 1982. It performed very well in both an air defense role and
in providing tactical support to the British troops.
The Harrier’s VTOL ability comes from its single-turbofan Pegasus engine. The Pegasus has four
AV-8 Harrier (Boeing Photo)
Unmanned Unmanned Air Air V VVehicles
V ehicles
swiveling jet nozzles, which can
be aimed straight downward for
VTOL, straight rearward for
forward thrust, at varying angles
downward for STOL and even
sideways. In fact, since the
nozzles rotate vertically through
98 rather than 90, the Harrier
can point its nozzles downward
and slightly forward and fly
backwards at speeds up to 30
mph. It can fly sideways up to
70 mph. Small attitude-control
jets in the wings are also fed by
the central power plant.
Unmanned air vehicles (UAV) are small, pilot-less aircraft that perform missions which do not
require a pilot onboard or which are considered too dangerous or politically unwise for manned flight.
Such missions include long- or short-range reconnaissance over hostile territory, electronic surveillance,
psychological warfare, destruction of enemy antiaircraft defenses or flying in environments
contaminated with nuclear, biological or chemical contaminants.
Unmanned air vehicles have been in existence since World War I. These vehicles were used during
World War II and in Korea, but it wasn’t until the Vietnam War that they became widely used. There
were 3,400 missions flown by UAVs during the Vietnam War with their widest use being for reconnaissance,
electronic surveillance and psychological warfare. Israel also used UAVs against the Egyptians
during the 1973 war and against Syria in 1982. During the Vietnam War, and by Israel against the
Arabs, the aircraft were called remotely piloted vehicles (RPV) because they were “flown’’ remotely
by a pilot either on the ground or in another aircraft. After the Vietnam War, the US Air Force lost
interest in RPVs because they were difficult to control and were often unreliable.
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